Many, if not most, glass containers, including a wide variety of bottles and jars, are, and for many years have been, manufactured by machines of the I.S. type, a type that uses a multiplicity of side-by-side sections each of which forms containers in a two-step molding operation. In a glass container forming operation of this type, a preform of the container, often called a parison or a blank, is formed in a first mold at a blank molding station of the I.S. machine section, either by pressing or blowing, and the blank is then transferred by a 180.degree. inverting operation in a vertical plane to a second mold of the I.S. machine section, often called a blow mold, for forming into the finished container by blowing. Typically, each container is provided with a threaded or otherwise contoured closure-receiving portion at its open end, which is usually referred to as a "finish," and the finish is formed by an assembly of separable segments that are joined end to end in an annular pattern during the formation of the finish, an assembly that is usually referred to as a "neck ring assembly" or a "neck mold assembly."
Each neck ring assembly is carried by an assembly that is used to transfer the parison from the parison mold to the blow mold, and the parison is carried by the neck ring assembly during the transfer to the blow mold. The assembly used to transfer the parison from the blank mold to the blow mold is usually referred to as an "invert arm assembly." Typically, each invert arm assembly carries two, three or four neck ring assemblies, each with a parison, depending on whether the associated I.S. machine is designed for double gob, triple gob or quadruple gob operation, and each invert arm assembly is made up of an opposed pair of arm segments that separate from one another when it is desired to remove the blown containers from their neck ring assemblies for further processing. After removal of the blown containers from the neck ring assemblies carried by the invert arm assembly, the invert arm assembly, with its neck ring assemblies, is then transferred back to the blank mold side, by another 180.degree. turning operation, for a repeat of the process.
From time to time in the operation of an I.S. machine it is necessary to replace the neck ring assemblies carried by an invert arm assembly, for example, as part of a job change to a container with a different size or type of finish or because of normal wear. Heretofore such neck ring assembly changes would be time consuming, requiring separation of the invert arm assembly segments, and followed by removal and replacement of neck ring assemblies, which were usually individually latched to opposed invert arm segments, an operation performed in a location not readily accessible and involving the prolonged usage of hand tools with an attendant risk that such tools could be dropped into the forming machine.
U.S. Pat. Nos. 3,233,999 (Mumford) and 3,617,233 (Mumford), the disclosure of each which is incorporated by reference herein, disclose prior art versions of invert arm assemblies for I.S. machines.